Oxiranes with amines

Few solid-phase syntheses of oxazoles have been reported (Table 15.17). The most general strategy is the dehydration of a-(acylamino) ketones (Entry 2, Table 15.17) or 2-(acylamino)phenols (Entry 1, Table 15.17). Oxazolidin-2-ones have been prepared by intramolecular nucleophilic cleavage of carbamates from insoluble supports (Entries 5 and 6, Table 15.17). Resin-bound 2-aminoethanols, which are accessible by nucleophilic ring-opening of oxiranes with amines, undergo cyclocondensation with aldehydes to yield oxazolidines [220,221]. These compounds are unstable towards acids, and can be released from the support only under neutral or basic reaction conditions. 

The isomerization of ethynyl-oxiranes 223 leads to furans 224, as illustrated in Scheme 128 <1969JCC12>. A similar reaction of ethynyl-oxiranes with amines gives pyrroles (see Scheme 86 in Section 4.2.3.3.1). Aziridine 225 reacts with bis(trimethylsilyl)acetylene upon heating to provide pyrrole 226 (Scheme 129) <1999JOC1630>. 

The invention of Heath et al. relates to novel phosphonate allyl monomers, made from reaction of an unsaturated oxirane with amine- or hy-drojyl-functionalized phosphonic acids (Scheme 3.21). These monomers were copolymerized with other unsaturated species (acrylic acid, maleic acid, acrylamide, or monomer derivatives of sulfonic acid, etc), yielding phosphonate polymers or oligomers. Phosphorus-containing monomers were incorporated at a ratio of 0.1-30% and polymerized in aqueous media. The final polymers had a molecular weight of 800-30 000 g mol . With their phosphonic acids groups (free acid or salts forms), they are of particular use as oilfield scale inhibitors. 

Epoxide Opening. LiC104 is an efficient promotor for the regioselective nucleophilic opening of oxiranes with amines, cyanide, azide, thiols, halides, and lithium acetylides. The regioselective opening of oxiranes with lithium enolates derived from ketones has also been observed in the presence of LiC104 (eq 6). ... 

Some examples of ring opening reactions with carbanions leading to five-membered heterocyclic ring formation are shown in Scheme 85. Pyrrole syntheses from functionally substituted oxiranes and amines are often described and typical examples are shown in Scheme 86. 

Group of plastics composed of resins produced by reactions of epoxides or oxiranes with compounds such as amines, phenols, alcohols, carboxylic acids, acid anhydrides and unsaturated compounds. 

Opening of the oxirane with tertiary butyl amine would then complete construction of the 3-blocking side chain (40). Displacement of chlorine by hydrazine then affords... 

In a second step, the gel is fimctionahzed for NA attachment. Common methods for polyacrylamide gel fimctionahzation are based on the treatment of the polymerized support with reagents such as hydrazine or ethylenedi-amine. These treatments generate amine groups in the gel that can react with amine-modified ONDs via glutaraldehyde coupling, or directly with oxidized DNA probes (Fig. 15). Alternatively, the fimctional groups may be introduced by copolymerization reactions (e.g. co-polymerization with N-hydroxysuccinimide acryhc or oxirane acryhc derivatives) [59]. 

Synthesis of primidolol (65) can be carried out by a convergent scheme. One branch consists in application of the usual scheme to o-cresol (62) ring opening of the intermediate oxirane with ammonia leads to the primary amine (63). The side chain fragment (64) can be prepared by alkylation of pyrimidone (63) with ethylene dibromide to afford Alkylation of ami noalcohol with halide ... 

Both, five- and six-membered cyclic carbamates have been synthesized by the reaction of 2-(l-haloalkyl)-oxiranes with C02 and primary aliphatic amines [81]. Notably, 5-substituted 2-oxazolidinones have been prepared in good yield (51-94%) by reacting 2-aminomethyloxiranes with C02 (0.1 MPa), in MeOH, at room temperature [82]. 

Das, U. Crousse, B. Kesavan, V. Bonnet-Del-pon, D. Begue, J.-P. Facile ring opening of oxiranes with aromatic amines in fluoro alcohols. /. Org. Chem. 2000, 65, 6749-6751. 

The amount of catalyst (scandium trisdodecyl sulfate) and ligand, (14), in the ring opening of czT-1,2-disubstituted oxiranes with primary and secondary aromatic amines in water were varied to maximize the yields.33 In all but two cases, the reaction, under ideal conditions, yielded the j3-amino alcohols in >81% yield with enantioselectivity ... 

Unsymmetric diacetylenic oxiranes react with amines to give pyrrole derivatives (Eq. 204). ... 

The ring-opening of oxiranes with ammonia and amines is one of the general methods for the preparation of 1,2-aminoalcohols. This procedure has acquired great importance in practice too. The process is illustrated in a new example in Eq. 317. ... 

A comprehensive study has been made of the kinetics of the reaction of oxiranes and amines, with special regard to the side-reactions and the role of the secondary products.The reaction of methyloxirane and dibutylamine has been investigated in an aprotic solvent to acquire information on the orientation of the ring scission.Some kinetic studies relating to this field are also worth of men-... 

Ph4SbOTf is an effective Lewis acid catalyst of nucleophilic addition of primary and secondary amines to oxiranes (Scheme 14.70) [142]. Ph4SbOH catalyzes the azidation of oxiranes with MejSiNj [143], the regioselectivity being dependent on the substituents of fhe oxiranes (Scheme 14.71). Ph4SbOMe promotes intramolec-... 

Scheme 2.2S Ring opening of oxiranes with the acidic amine-HF reagent 70% HF-pyr is poorly selective and leads to the formation of oligomeric byproducts [70],...

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